Definition of Term

zona radiata

(english)
A thickened, rather complex egg membrane of teleost fishes, which often has a radiate appearance. It is formed at the surface of the egg by the ooplasm, or the ooplasm and the follicle cells and hence should be regarded as a true vitelline membrane. May be overlain by the chorion. In Elasmobranchii the zona radiata underlies or overlies a homogeneous vitelline egg membrane.
(See also: chorion)